In 2010, adults in the United States weighted an average of 168 pounds. In 2012, a researcher in a sample of 200 adults finds an average weight of 182 with a standard deviation of 3 pounds. What is...

In 2010, adults in the United States weighted an average of 168 pounds.  In 2012, a researcher in a sample of 200 adults finds an average weight of 182 with a standard deviation of 3 pounds. What is the dependent and independent variable for this study?